<% let years = []; posts.forEach((item) => { const year = item.date.substring(0, 4); if (!years.includes(year)) { years.push(year); } }); %>

<div class="archives-container">
  <% years.forEach(function(year) { %>
    <h2 class="year"><%- year %></h2>
    <% posts.forEach(function(post) { %>
      <%if (post.date.indexOf(year) !== -1) { %>
        <article class="post">
          <a href="<%= post.link %>">
            <h2 class="post-title">
              <%= post.title %>
              <small><%= post.dateFormat %></small>
            </h2>
          </a>
        </article>
      <% } %>
    <% }); %>
  <% }); %>
</div>
